in Burns : Journal of the International Society for Burn Injuries (in press)

Background: Burn patients are at risk of vitamin D (VD) deficiency and may benefit from its pleiotropic effects as soon as acute phase. Aim of this observational study was to assess effects of a ... [more ▼]

Background: Burn patients are at risk of vitamin D (VD) deficiency and may benefit from its pleiotropic effects as soon as acute phase. Aim of this observational study was to assess effects of a cholecalciferol (VD3) bolus on VD status in adult burn patients (Group B, GB) after admission, compared to healthy subjects (Group H, GH). Methods: Both groups received an oral dose of 100,000 IU VD3. Blood samples were collected before (D0) and 7 days (D7) after bolus to measure 250H-D, 1,25(OH)2-D, parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23). Albumin (ALB) and VD binding protein (DBP) were measured and used to calculate free 25OH-D level. Data were expressed as median (min–max) or proportions. Results: A total of 49 subjects were included: 29 in GH and 20 in GB. At D0, prevalence of VD deficiency was higher in GB: 25OH-D was 21.5 (10.1–46.3) ng/ml in GH vs 11 (1.8–31.4) ng/ml in GB. DBP and ALB were lower in GB. At D7, DBP was stable in both groups while ALB decreased in GB. 25OH-D increased by 66.6 (13.5–260.3)% in GH. In GB, changes in 25OH-D extended from 36.7% to 333.3% with a median increase of 33.1%. Similar changes were observed in each group for free 25OH-D. High FGF23 levels were observed in GB. Conclusions: This study highlighted the differences in VD status and in response to a high dose VD3 in burn patients when compared to healthy patients. Pitfalls in VD status assessment are numerous during acute burn care: 25OH-D measurement needs cautious interpretation and interest of free 25OH-D is still questionable. They should not prevent burn patients to receive VD supplements during acute care. Higher doses than general recommendations should probably be considered. [less ▲]

Urolithiasis is a common condition, with a prevalence of 10% and a male/female ratio above 1 according to large national series. Various types of urinary stones have been described upon their mineral ... [more ▼]

Urolithiasis is a common condition, with a prevalence of 10% and a male/female ratio above 1 according to large national series. Various types of urinary stones have been described upon their mineral content and/or their morphology. Hence, a combined morpho-constitutional (M-C) classification has been proposed. In order to detail the prevalence of urolithiasis in general and of each M-C type in particular upon age and gender in Belgium, we retrospectively studied the database of a reference center for urolithiasis analysis. Between 2010 and 2013, 2195 stones were characterized. We excluded 45 nonbiological stones and 281 stones, which originated from outside the study zone. Among 1869 stones,1293 (69.2%) affected men. Prevalence peak of urolithiasis was observed between 50–60 years of age in both genders. The M-C analysis was available for 1854 stones (99.2%): multiple morphological types were concomitantly identified in 49.3%. In the whole population, the main mineral constituent was whewellite (54.4%), mainly organized as type Ia (94%). Weddellite was found in 19.8%, with an equal distribution between types IIa and IIb. Uric acid was the 3rd most frequent constituent in man, with a similar distribution between IIIa and IIIb. Phosphate was uncommon in man (8.2%), but frequent in woman (26.6%) with a type IVa1 organization. Prevalence of M-C types changes with aging, i.e. decrease of weddellite and increase of whewellite and uric acid in both genders. This retrospective analysis of a single-center database of urinary stones helps characterize the M-C epidemiology of urolithiasis in Belgium. [less ▲]

BACKGROUND: Bone-specific alkaline phosphatase (BAP) is now recommended to assess bone turnover in hemodialysis (HD) patients. However, little is known about potential variability between methods ... [more ▼]

BACKGROUND: Bone-specific alkaline phosphatase (BAP) is now recommended to assess bone turnover in hemodialysis (HD) patients. However, little is known about potential variability between methods available to measure BAP. METHODS: We measured BAP in 76 HD patients with six different assays (Beckman-Coulter Ostase IRMA, Beckman-Coulter Ostase Access, IDS iSYS Ostase, IDS Ostase enzyme immunoassay, DiaSorin Liaison Ostase and Quidel MicroVue BAP). RESULTS: We observed a high correlation between all the assays ranging from 0.9948 (IDS iSYS vs. IDS EIA) to 0.9215 (DiaSorin Liaison vs. Quidel MicroVue). However, using the regression equations, the equivalent concentration of a Beckman-Coulter Access value of 10μg/L can range from 7.7 to 14.4μg/L and of 20μg/L can range from 16.9 to 27.9μg/L with other assays. According to Beckman-Coulter Access, 13%, 50% and 37% of the patients presented BAP values ≤10, between 10 and 20 and ≥20μg/L, respectively. Discrepancies are observed when other assays are used (concordance from 10 to 100%). CONCLUSIONS: Analytical problems leading to inter-method variation should be overcome to improve the usefulness of this marker in clinical practice. According to correlation results, recalibration of BAP assays is necessary but should not be a major issue. [less ▲]

Background: Standardization of parathyroid hormone (PTH) assays is a major issue, especially in hemodialyzed (HD) patients. Two automated third generation PTH assays (Roche Elecsys and DiaSorin Liaison) are now available. These assays are specific for the (1-84) PTH and do not cross-react with the (7-84) fragment, contrary to second generation (intact) assays. We aimed to calibrate the two methods against the WHO International PTH Standard (IS) 95/646 to see if the two assays could provide comparable results in a population of healthy subjects, HD patients and patients suffering from primary hyperparathyroidism (PHP). Methods: We selected 79 healthy subjects and two populations of patients presenting PTH disorders: 56 HD and 27 PHP patients. We reconstituted the IS in a pool of human serum containing undetectable levels of 1-84 PTH and prepared 13 serum standards ranging from 0 to 2000 pg/mL. The standards were run on the two instruments to calibrate the assays on the IS. The different populations were run before and after restandardization. Results: As these kits were differently calibrated, the results obtained after restandarization were significantly different. Restandardization process improved concordance between assays and, taking the analytical variability of the two kits into account, the results could be considered to be similar. Conclusions: Restandardization of automated third generation PTH assays with the WHO 1-84 PTH Standard significantly reduces inter-method variability. Reference ranges and raw values are totally transposable from one method to the other in healthy subjects, but also in diseased patients, e.g., with HD or those suffering from PHP. [less ▲]